Brush-raising device.



w. STRUTL BRUSH RAISING DEVICE.

APPLICATION FILED DEC. 18, 19M.

Patented Jan. 1, 1918.

yymmeas .1 1 iii m ATTORNEY .7

UN T D sT T s ATE T OFFIOE.

WILLIAM 'STRUTT, or-PITTsBURGH, PENNsYLvANrA, AssIGNon TowEsTINeHoUsE nLEo'rnIo AND MANUFACTURING COMPANY, A CORPORATION OF PENNSYLVANIA.

BRUSH-RAISING DEVICE.

To all whom it may concern:

Be it known that I, lVILLIAM STRUTT, a

citizen of the United States, and a resident of Pittsburgh, in the county of Allegheny and State of'Pennsylvania, have invented a new and useful Improvement in Brush-Rais ing Devices, of whichthe following is a specification.

My invention relates to dynamo-electric machines and particularly to means for temporarlly'raising brushes out of engagement with the commutator cylinders thereof.

The object of my invention is to provide a simple and effective briish-raising device which shall be particularly useful when used in connection with rotary converters and similar synchronous machines that have main and commutating pole field windings details of the brush-raising mechanism.

A field framel serves to support an endbell structure 2 that consists of an outer ring 3 in engagement with the field frame and a number of radially extending arms 1 which carry a rocker ring 5. The rocker ring 5 serves as a support for a plurality of regularly spaced, laterally and radially extending brackets 6, each of said brackets com prising a bar 7 that extends parallel to, and

is spaced a suitable distance from, the commutator cylinder 8. Each of the bars 7 carries a'plurality of brush holders 9 that are rigidly secured thereto. The brush holders severally comprise box-like structures 10 for the brushes 11 that bear upon, and are resiliently maintained in engagement with, the commutator cylinder 8 by means of springs 12.

The rocker ring 5 carries a pinion 13 that is fitted on a shaft 14 and is secured thereto by means of a nut 15 and a washer 16. The shaft 14 extends through and beyond the rocker ring 5 and supports a lever 17 that is retained on the shaft end by a suitable pin 18. A second ring 19 carries a rack 20 adapted to engage the pinion 13 and is provided, on its outer circumferential face, with Specification of Letters Patent. i

Patented Jan. 1 1918.

Application filed December 18, 1914. Serial No. 877,962.

a reduced portion 21 to form a bearing surface'for the innerface of the rocker ring 5. A plurality of bolts 22, provided with washers 23 and 241, serve to hold the ring 19 in proper relation to the rocker ring 5, so that the rack 20 will always be held in mesh.

with the pinion 13. Thus, the'ring 19 may be rotated with respect to the rocker ring 5 I bymeans of the lever 17 The ring 19 car ries a plurality of regularly "spaced lever arms 25 pivotally mounted thereon by means of tap bolts 26 and washers 27. The lever arms 25 are formed of astrong and durable fibrous insulating material that may be easily machined, thereby eifectively insulating the brush-raising device from the frame of the machine. An ar 28 is provided, at one end, with a bifurcated portion 29 that embraces the free end of the lever arm 25' and is rigidly secured thereto by any suitable means, such as a bolt 31 and 'a nut 32. A second bifurcated portion embraces a second lever arm 33 and is fastened thereto by: a stud 3 1 and co'tterpins 35 to provide a pivotal connection between the members. The lever arm 33 i's'rigidly secured, at its other end, to a rod 36 by means of a set screw 37. The rod 36 'extendsparallel to the brush holder supporting frame '1 j and is rotatably mounted in brackets 38 carried thereby. The rod 36 carries a suitable cam member that is adapted to engage extensions 40 attached to the upper portions of the brushes 11f Thecammember comprises a bar 39 that extends the length of the rod 36 and issupported parallel to and at a dis tance therefrom by the arms 41 that extend" through holes in the rod. The arms ll are provided with threaded portions and coacting nuts 42 so that the distance between the bar 39 and the rod 36 may be adjusted.

A modification of the brush-raising mechanism is shown in Fig. 3 wherein the rod 36 is provided with a plurality of eccentric cam members 13 each of which is adapted to engage a single brush extension.

In order to raise the brush out of engagement with the commutator cylinder, the operating lever 17 is moved in a clockwise direction to produce a counterclockwise rotative movement of the ring 19 and of the lever arms 25. The lever arms 25, in turn, cause movement of the. lever arms 33 and the rod 36 which thus bring the cam members into engagement with the brush extensions 40, with the result that the brushes are moved upwardly and out of engagement with commutator cylinder 8.

hen it is desired to return the brushes into engagement with the commutator cylinder, the operating lever is moved to the position shown in the drawings, whereupon the cam memberswill become disengaged from the brush extensions, and the springs 12 will return the brushes to their original positions. j j

The project-ions upon the brushes are so designed that they will always he slidably engaged with the cam members until the brushes are worn down to such a degree that they are no longer serviceable and, since there is no rigid connection between the brushes and the lifting means, no manual adjustment ofthe device is required to compensate for wear on the brushes.

Vhile I have shown my invention in a simple and preferred form, it is not so limited, but is capable of various modifications of its structural features and other arrangements and location of parts such as may come within the scope of the ,appended claims.

I claim as my invention:

1. A brush-raising mechanism for dynamo-electric machines comprising a brush holder, a cam device one member of which is carried by the brush and the other mem ber of which is rotatably mounted, and means for actuatingsaid rotatably mounted member to cause it to slidably engage said brush-carried member and raise the brush.

2. A bruslrraising device for dynamoelectric machines comprising a projection carried by the brush, a rotatably mounted cam member, and means for actuating said cam member to cause it to slidably engage said brush-carried projection.

3. A brush-raising device fordynamoelectric machines comprising a brush holder,

a projection carried by the brush, a cam member adapted to engage the projection, and means for actuating the cam member Copies of this patent may be obtained for five cents each, by addressing the Gommi-ssionerof Patents,

to cause it to engage the projection and raise the brush, the said cam being adjustably mounted whereby the travel of the brush may be varied.

4. I11 a dynamo-electric machine, the combination with a support, a brush holder carried thereby, a projection carried by the brush and a rod rotatably mounted upon the support, of an arm carried by the rod and adapted to slidably engage said projection upon the rotation of the rod and to raise the brush. I

5. In a dynamo-electric machine, the combination with a support, a brush holder carried thereby, a projection carried by the brush and a rod rotatably mounted upon the support, of an arm carried by the rod for engaging said projection and raising the brush, the said arm being adjustable with respect to the rod whereby the travel of the brush may be varied.

6. In a dynamo-electric machine, the combination with a support, aplurality of brush holders carried thereby, projections carried by the respective brushes and a rod rotatably mounted upon the support, of an arm carried by the rod for engaging. the said projections and simultaneously raising all of the brushesk 7. In a dynamo-electric machine, the 001m bination with a support, a plurality, of brush holder carried thereby, projections carried by the respective brushes and a rod rotatably mounted upon the support, of a U- shaped arm, the end portions of which are secured to the rod and the intermediate portion of which is adapted to engage the said projections and to simultaneously raise all of the brushes.

Intestimony whereof, I have hereunto subscribed my name this 12th day of Dec, 1914-. l

' WILLIAM STRUTT.

\Vitnesses:

' PARKER N mm, B. B. I-IINEs.

Washington, D. G. 

